Guide · Agent skill
How to use the 3D Sky Background agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The 3D Sky Background skill is an agent skill that teaches an AI coding agent to build a sky for a 3D scene as a full environment, not a flat backdrop. It covers the visible sky, the reflections and ambient light, and the direct sun, so they agree. This guide is for developers and designers working on outdoor or architectural 3D scenes in a web or real-time engine. By the end you will know how to install the skill, ask for sky work in plain language, and check the result.
3D Sky BackgroundMengTo/Skills · MIT Download the skill Quick start
- 1Download and unzip. Download the skill ZIP from this page and unzip it so you have a 3d-sky-background folder.
- 2Place the folder. Move it to ~/.claude/skills/ for personal use, or to .claude/skills/ inside your project. Alternatively, upload it under Settings → Capabilities → Skills in the Claude apps.
- 3Confirm your project fits. Make sure you have a 3D rendering project, such as Three.js, that the agent can read and edit.
- 4Describe the sky you want. Use a plain request that names the scene, time of day or sky type, and whether the camera moves freely.
- 5Provide assets if you have them. If you want a panorama, supply a licensed image and say what the sun position should be.
- 6Test the result. Ask the agent to check a full orbit, the zenith view, the seam and the hero view for sun, shadow and reflection agreement.
What is an agent skill, and what does this one do?
An agent skill is a folder of instructions and supporting files that an AI agent loads when a task matches the skill's description. This one is named 3d-sky-background. Its description says it is for camera-correct sky backgrounds with a procedural atmosphere or panorama, horizon haze, aligned sunlight, and coherent environment lighting.
When it is active, the agent inspects your renderer, camera range, colour pipeline, environment lighting and existing assets before choosing a method. It can use a procedural sky when changing sun position matters, a panorama when cloud composition matters, or a mix of both. It keeps the project's existing rendering backend and does not add a second renderer for the sky.
- Keeps the visible sky, reflection/ambient environment and direct sun lighting as separate responsibilities.
- Makes the sun direction shared across the visible disk, glow, directional light and any sky-ray pass.
- Checks seams, stretched clouds, colour errors and slow lighting rebuilds.
- Handles day, dusk and night changes with continuous weights.
Install the skill from the ZIP or the Claude apps
Download the ZIP for this skill from this page and unzip it. The skill folder contains agents/openai.yaml, REFERENCES.md and SKILL.md. Put the unzipped folder in one of these locations:
For a personal install across projects, place it in ~/.claude/skills/. For a single project, place it in that project's .claude/skills/ folder. In the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.
- Personal: ~/.claude/skills/3d-sky-background
- Project: .claude/skills/3d-sky-background inside your project
Check that your project is a good fit
The skill needs a 3D rendering project, such as one built with Three.js, where the agent can read and edit code. If you plan to use a panorama, you need a licensed panorama image. The skill does not require one, but it is listed as optional.
The guidance assumes real-time 3D engine concepts such as PMREM and clipping ranges. It is not aimed at 2D illustrations or static images, and it is not useful for projects that do not use a 3D renderer.
- Required: a 3D rendering project the agent can read and edit.
- Optional: a licensed panorama image if you use an existing sky texture.
- Runs scripts: no. Uses network: no.
Trigger the skill with natural requests
You do not need a special command. Describe the sky you want in plain language, and mention the outdoor, lighting or time-of-day context. The skill's description lists architectural skies, outdoor 3D backgrounds, golden hour and day-to-night sky transitions as its main triggers.
Give the agent your project's context where you can, such as the renderer, whether the camera rotates freely, and whether you have a sky image. This helps it choose between a procedural and a panorama approach.
- "Add a procedural sky with a pale warm horizon to my Three.js architecture scene."
- "Set the sun to golden hour and make the sky, fog and sunlight match."
- "I have a licensed panorama. Map it so its sun lines up with my scene sun, and check the seam."
- "Make a day-to-night transition for the sky without rebuilding the environment every frame."
Review what the agent produces
The skill asks for a stable surrounding sky. A dome, if used, must fit inside the camera's clipping range and follow camera translation. Panoramas should be rotated so the photographed sun matches the scene sun. For partial landscape photos, the guidance says to record angular coverage and horizon position, and not to stretch the image over a sphere.
Ask the agent to test the sky while orbiting the camera, not only from the first view. The skill's checklist includes a full orbit, a vertical look, the hero view, transitions and mobile or 2× rendering.
- Full orbit and vertical look: no seam, stretched clouds, dome edge or parallax.
- Sun direction, shadows, rays and reflections agree at the hero view.
- Day, dusk and night changes avoid flashes, double tone mapping and mismatched fog.
- The sky still works before its image loads and if the image fails.
Safety notes: scripts and network
According to the listing, this skill runs no scripts and uses no network. Its files are instructional: SKILL.md, REFERENCES.md and agents/openai.yaml. REFERENCES.md links to external documentation and a source file for reference, but the skill itself does not fetch them.
Still review any code the agent writes before you run it, and check where any sky image came from. Only use panorama images you have a licence to use.
- Runs scripts: no.
- Uses network: no.
- Check that any panorama you add is licensed for your use.
What people use it for
- Adding a procedural sky with horizon haze to an architectural visualisation built in a web engine.
- Matching sun direction, shadows and reflections for a golden hour shot.
- Replacing a flat background image with a sky that lights PBR materials.
- Building a day-to-night transition that fades stars in after the sky darkens.
- Mapping a licensed panorama so its sun lines up with the scene sun and its seam stays hidden.
Frequently asked questions
How do I install the 3D Sky Background agent skill?
Download the ZIP from this page and unzip it. Place the 3d-sky-background folder in ~/.claude/skills/ for personal use or in a project's .claude/skills/ folder. In the Claude apps, you can upload it under Settings → Capabilities → Skills.
What does the 3d-sky-background skill require?
It requires a 3D rendering project, such as Three.js, where the agent can read and edit code. A licensed panorama image is optional and only needed if you want to use an existing sky texture.
Is the 3D Sky Background skill free?
The listing states the skill is released under the MIT licence. Check the licence file in the source repository for the exact terms before you rely on it in a commercial project.
Does this skill run scripts or use the internet?
According to the listing, it runs no scripts and uses no network. Its files are instructions for the agent, but you should still review any code the agent generates.
Can I use it with engines other than Three.js?
The listing names Three.js as an example of a suitable project. The guidance assumes real-time engine concepts such as PMREM and clipping ranges, so it is best suited to projects that use a 3D renderer like these.
Is it suitable for 2D illustrations or static images?
No. The listing says it targets real-time 3D rendering pipelines, so it is not meant for simple 2D illustrations or static images.
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Our verdict
Use this skill if you build outdoor or architectural 3D scenes in a real-time engine and need a sky whose sun, reflections and lighting agree. Pick something else if you only need a static backdrop, a 2D illustration, or a project with no 3D renderer.
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